Structural unit



Feb. 14, 1939.

c. J; O'BRIEN STRUCTURAL UNIT Filed Feb. 15, 1937 4 H 4 j. a p. A d. 5

4 4 I H a, v 5::

:\ I V I 7 4 v I v BY I I ATTORNEY.

Patented Feb. 14, 1939 UNITED STATES PaTENT oFF cE 6 Claims.

This invention relates in general'to a reinforcing structural unit for beams, joists, and the like, and has more particular reference to-a reinforcing unit of this kind in which the stirrup elements or some of them are provided with integral supporting legs or form spacing units.

An important object of the invention is in the provision of a concrete reinforcing. structural unit for joists, beams, and the like, adapted to reinforce the beams against the various strains to which they are subjected.

A further object of the invention is in the provision of an improved structural unit for reinforcing concrete beams which comprises a combined chair and stirrup havingmeans for spacing them in a form to which they are applied.

A still further object of the invention is to produce a structural unit of this kind which will formthe necessary chairs, stirrups and spacers with a minimum number of parts.

Other objects of the invention will appear hereinafter, the accompanying drawing illustrating preferred embodiments of the invention in which,

Pig. 1 is a perspective view of one of the units; Fig. 2 isa sectional view showing a unit cast in place in a concrete form; Fig. 3 is a perspective view of a stirrup; Fig. 4 is a perspective of a combined stirrup and spacer forming element; and

Fig. 5 is a perspective view of a modification. In applying a structural unit composed of metal bars or rods to the forms for casting a concrete beam or joist it is desirable that the units be supported in spaced relation to the outer or broken. In the present invention these ob.v

J'ects are accomplishemby making the elements of a simple form so "that they can be combined tural part thereof.

Referring now more particularly to the draw-,

50 ing, this improved structural /unit comprises a plurality of unitary stirrup elements It), each of which is substantially U-shaped, havlngoutwardly' bent extremities ll. These stirrup elements arerigidly attached and secured together in up- 55 right spaced relation by means of longitudinally to provide a stirrup with projecting supporting. legs forming a material and easily attached strucextending rods l2, l3, I4 and i5 which are 10- J cated at the tops and bottoms of the U-shaped sides and in the angle of the lateral extensions H adiacent the tops thereof.

These bars and elements ID are usually attached 5 together by welding, either electrically or in any other suitable manner, so that they present a fixed rigid structure which is adapted to be set in place in the formation of a concrete beam, joist, and the like. i In the structural unit, at either end, or intermediate the unitary structural elements Ill are supporting and spacing elements, each comprising a pair of substantially Z-shaped bar members l6 having an extremity H at one end co'r- 16 responding to the bent extremities of the unitary elements l0 and having an angularly bent portion I 8 at the other end, and an outwardly or downwardly turned leg at the extremity of this portion. Two of these members l6 are :0 placed oppositely so that their extremities II will be parallel to the extremities ll of an element It) and the bottom portions l8 will be placed together with the legs I9 at the opposite sides of the lower end of the structural element thus formed, the portions it being rigidly and permanently attached to each other by welding or securing them at spaced spots or along their contactin'g edges so that when thus attached they are of substantially the same shape as the unltary elements III with the exception that they have supporting legs la projecting at each side. of the lower end thereof. 7

When these elements I0 and I6 are combined and attached in spaced relation by the rods I2, I3, l4. and I5 as shown in Fig. 1, the unit is complete for incorporating it in a concrete structure.

I A concrete receiving form is made usually of boards. 20, 2|, and 22 to constitute a beam at the lower side of a floor and a mass of concrete 23 40 is vured in the form an .allowed to set and har en. Before the concre e is poured into the form a structural unit as shown in Fig. 1 is inserted from the top into the form and if ofthe proper dimensions the legs l9 will extend into the corners or angles at the bottom of the form, thereby spacing it properly fromthe bottom and sides of the formso that only the extremities of the legs can possibly be visible in the completed beam structurewhich will be left when theforms Qare removed.

A.si milar structure is shown in Fig. 5 except that the structuratelements l0 and I6 have extremities II' and I1 along one side which are turned inwardly.

cause the stirrup elements are so supported.

spaced and positioned that nothing is left tothe skill or attention of a workman in placingthe structural units in the forms. .The reinforcing bars hold the elements in proper spaced relation, the supporting feet or legs properly space the bars and also the elements from the sides of a form and prevent any portion of the structural unit from resting against the side of the, form to be visible in the concrete beam when the form is removed. 'Ihesestructuralunits are also inexpensive for production and may be conveniently and easily handled in actual use.

I claim: 7

1. A structural unit comprising a plurality of U-shaped stirrups and longitudinal rods secured thereto and spacing them apart, some of the stirrups comprising two similar members with 30 intermediate portions in contact and secured toalong which they are secured together forming. a

double bottom portion with the bent extremities at the ends forming supporting legs.

3. A stirrup element'for a structural unit open at the top. comprising a pair of Z-shaped bars placed. oppositely together and having 'parallel portions in contact to form a double bottom along which they are secured together, .with one extremity of each bar projecting beyond the contacting portion to provide a supporting leg.

4. A structuralunit reinforcing element closed at the bottom and open at the top comprising a pair of similar bars having bent ends placed oppositely against each other to form a double bottom upon which they are secured together to form a rigid unit with extremities projecting be-- yond the bottom portion to provide a supporting standing therefrom, the bottom portions bein rigidly secured together and the extremities oi the ends of each bar being bent oppositely to form a lower leg and an upper spacing extension at opposite sides of the unit.

CHESTER J. O'BRIEN.

- from and the bent extremities of each bar ex- 

